Field of the Invention
The present invention relates to an optical unit and an image pickup apparatus using the same.
Description of the Related Art
An optical unit which forms a plurality of images simultaneously by using one optical system has been proposed in U.S. Pat. No. 8,784,301 Specification, and Japanese Patent Application Laid-open Publication No. 2012-27228.
In U.S. Pat. No. 8,784,301 Specification, an image pickup unit which captures two optical images simultaneously has been disclosed. The image pickup unit includes a lens assembly and a sensor assembly. An optical image of an object is formed by the lens assembly.
The sensor assembly includes a prism structure and an image sensor which is on a same plane. The prism structure includes a prism assembly, a reflector unit, and a prism.
In the sensor assembly, light is split into two at a boundary of the prism assembly and the reflector unit. Accordingly, a first optical path is formed in the prism assembly and a second optical path is formed in the reflector unit. As a result, a first optical image is formed on the first optical path and a second optical image is formed on the second optical path.
A first image pickup sensor is disposed on the first optical path. The first optical image is captured by the first image pickup sensor. A second image pickup sensor is disposed on the second optical path. The second optical image is captured by the second image pickup sensor.
In Japanese Patent Application Laid-open Publication No. 2012-27228, a color image pickup optical system which captures four optical images simultaneously has been disclosed. The color image pickup optical system includes an image pickup lens, a color separation prism, and an image pickup element. The color separation prism is a prism of Koester type.
The color separation prism has a structure in which an equilateral triangle has been divided into two equal parts. By divided the equilateral triangle into two equal parts, the color separation prism is divided into two right-angled triangle members. Each of the two right-angle triangle members has a structure of an equilateral triangle divided into two equal parts.
The color separation prism is provided with a first color separation surface, a second color separation surface, and a third color separation surface. At the first color separation surface, incident light is separated into two color components, and is divided in to light transmitted and light reflected. At the second color separation surface, one of the lights separated at the first color separation surface is separated further into two color components. At the third color separation surface, the other light separated at the first color separation surface is separated further into two color components.
In the color separation prism, a first optical path and a second optical path are formed by the first color separation surface and the second color separation surface, and a third optical path and a fourth optical path are formed by the first color separation surface and the third color separation surface. An optical image is formed in each of the four optical paths.
One image pickup element is disposed on side of a surface of emergence of the color separation prism. Four optical images are captured by the one image pickup element.